“Is the upgrade procedure for a high-availability pair of Cisco Wireless LAN Controllers the same as the procedure for a single Cisco WLC?” Several customers asked me this questions and the answer is YES.

First you check the current and backup firmware image.

(Cisco Controller) >show boot
Primary Boot Image…………………………. 8.2.111.0 (default) (active)
Backup Boot Image………………………….. 8.1.102.0

Next you check if your SSO configuration is working as expected.

(Cisco Controller) >show redundancy summary
Redundancy Mode = SSO ENABLED
Local State = ACTIVE
Peer State = STANDBY HOT
Unit = Primary
Unit ID = 00:81:C4:87:3B:C9
Redundancy State = SSO
Mobility MAC = 00:81:C4:87:3B:C9
BulkSync Status = Complete
Average Redundancy Peer Reachability Latency = 177 Micro Seconds
Average Management Gateway Reachability Latency = 935 Micro Seconds

Upload the new firmware to the controller by using an TFTP or FTP server. I am using an TFTP server in this example.

(Cisco Controller) >transfer download datatype code
(Cisco Controller) >transfer download filename AIR-CT5520-K9-8-2-141-0.aes
(Cisco Controller) >transfer download path .
(Cisco Controller) >transfer download serverip 10.200.8.83
(Cisco Controller) >transfer download mode tftp
(Cisco Controller) >transfer download start

After the TFTP session is finished you’ll notice that the the software is automatically transferred from the active to the standby unit.

TFTP Code transfer starting.

TFTP receive complete… extracting components.

Checking Version Built.

Image version check passed.

Informing the standby to start the transfer download process

Waiting for the Transfer & Validation result from Standby.

Standby – Standby receive complete… extracting components.

Standby – Image version check passed.

Transfer & validation on Standby success, proceed to Flash write on Active.

Writing new AP Image Bundle to flash disk.

Executing fini script.

File transfer is successful.
Reboot the controller for update to complete.
Optionally, pre-download the image to APs before rebooting to reduce network downtime.

Transfer Download complete on Active & Standby

The last step is to reload both controllers to activate the firmware. After you reboot the active controller, you are able to access the standby controller and reboot that controller too. You have the option to reboot both controllers with one command.

(Cisco Controller) >reset system both in 00:05:00 image no-swap reset-aps

The controller also has the option to pre download the firmware from the controller to the access-points. This speeds up the upgrade process for the access-points, because the access-point don’t need to download the firmware after the controllers are online again. The access-point only need to reboot when the loose the connection with the controller. I will describe this process in a separate post.

After the controllers are back online, you should check the primary and backup boot firmware to see if the upgrade was successful.

(Cisco Controller) >show boot
Primary Boot Image…………………………. 8.2.141.0 (default) (active)
Backup Boot Image………………………….. 8.2.111.0

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René Jorissen

Co-owner and Solution Specialist at 4IP Solutions

René Jorissen works as Solution Specialist for 4IP in the Netherlands. Network Infrastructures are the primary focus. René works with equipment of multiple vendors, like Cisco, Aruba Networks, FortiNet, HP Networking, Juniper Networks, RSA SecurID, AeroHive, Microsoft and many more. René is Aruba Certified Edge Expert (ACEX #26), Aruba Certified Mobility Expert (ACMX #438), Aruba Certified ClearPass Expert (ACCX #725), Aruba Certified Design Expert (ACDX #760), CCNP R&S, FCNSP and Certified Ethical Hacker (CEF) certified. You can follow René on Twitter and LinkedIn.

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